Ruthenium catalysts, and use thereof for Fischer-Tropsch synthesis

Abstract

A novel ruthenium catalyst, notably a ruthenium-titania catalyst, is disclosed to which is added sufficient rhenium to obtain, at corresponding process conditions, improved activity maintenance in the production of hydrocarbons via carbon monoxide-hydrogen synthesis reactions vis-a-vis a catalyst composition otherwise similar except that it does not contain rhenium. High quality middle distillate fuels, characterized generally as admixtures of linear paraffins and olefins, are formed in a process wherein a feed mixture of carbon monoxide and hydrogen are contacted at reaction conditions over such catalyst.

What is claimed is: 
     
       1. A process useful for the synthesis of hydrocarbons at reaction conditions from a feed constituting an admixture of carbon monoxide and hydrogen, which comprises contacting said feed with a catalyst which comprises ruthenium in catalytically active amount composited with titania, or titania-containing support, having a rutile:anatase ratio of at least about 2:3 and rhenium in amount sufficient to provide a weight ratio of rhenium:ruthenium which ranges from about 2:1 to about 1:4,sufficient at corresponding reaction conditions to obtain improved activity maintenance vis-a-vis a ruthenium catalyst otherwise similar except that it does not contain rhenium. 
     
     
       2. The process of claim 1 wherein the catalyst contains from about 0.01 percent to about 8 percent ruthenium, based on the weight of the catalyst composition. 
     
     
       3. The process of claim 1 wherein the catalyst contains from about 0.2 to about 4 percent ruthenium, based on the weight of the catalyst composition. 
     
     
       4. The process of claim 1 wherein the catalyst contains from about 0.01 to about 8 percent rhenium, based on the weight of the catalyst composition. 
     
     
       5. The process of claim 1 wherein the catalyst contains from about 0.1 to about 4 percent rhenium, based on the weight of the catalyst composition. 
     
     
       6. The process of claim 1 wherein the reaction conditions are defined within ranges as follows:   ______________________________________                                    
H.sub.2 :CO mole ratio                                                    
                    about 0.1:1 to 10:1                                   
Space Velocities hr.sup.-1                                                
                    about 100 to 20,000                                   
Temperatures, °C.                                                  
                    about 150 to 500                                      
Pressure, kP.sub.a  about 100 to 10.sup.5.                                
______________________________________                                    
     
     
     
       7. The process of claim 1 wherein the reaction conditions are defined within ranges as follows:   ______________________________________                                    
H.sub.2 :CO mole ratio                                                    
                    about 0.5:1 to 4:1                                    
Space Velocities, hr.sup.-1                                               
                    about 300 to 2000                                     
Temperature, °C.                                                   
                    about 180 to 300                                      
Pressure, kP.sub.a  about 100 to 3100.                                    
______________________________________                                    
     
     
     
       8. The process of claim 1 wherein the rutile:anatase ratio of the titania of the catalyst support ranges from about 2:3 to about 100:1. 
     
     
       9. The process of claim 1 wherein the rutile:anatase ratio of the titania of the catalyst support ranges from about 3:2 to about 100:1, and greater. 
     
     
       10. The process of claim 1 wherein the rutile:anatase ratio of the titania of the catalyst support ranges from about 2:3 to about 100:1, and the catalyst contains from about 0.01 percent to about 8 percent ruthenium, based on the weight of the catalyst composition. 
     
     
       11. The process of claim 10 wherein the catalyst contains from about 0.2 percent to about 4 percent ruthenium. 
     
     
       12. The process of claim 1 wherein the rutile:anatase ratio of the titania of the catalyst support ranges from about 2:3 to about 100:1, and the catalyst contains from about 0.01 percent to about 8 percent rhenium. 
     
     
       13. The process of claim 12 wherein the catalyst contains from about 0.1 to about 4 percent rhenium. 
     
     
       14. The process of claim 1 wherein the rutile:anatase ratio of the titania of the catalyst support ranges from about 2:3 to about 100:1, the catalyst contains from about 0.01 percent to about 8 percent ruthenium, and from about 0.01 percent to about 8 percent rhenium, based on the weight of the catalyst composition. 
     
     
       15. The process of claim 14 wherein the catalyst contains from about 0.2 to about 4 percent ruthenium, and from about 0.1 to about 4 percent rhenium.